METHOD AND APPARATUS TO DIMINISH AERODYNAMIC DRAG ON TRUCKS, TRAILERS AND OTHER MOVING VEHICLES

PROCEDE ET APPAREIL POUR DIMINUER LA TRAINEE AERODYNAMIQUE EXERCEE SUR DES CAMIONS, DES REMORQUES ET AUTRES VEHICULES MOBILES

English Abstract

A significant portion of fuel consumption of trucks is used to overcome
aerodynamic drag and wind
resistance. Many treatments have been applied to the front of truck surfaces
and underneath trailers to
improve vehicle aerodynamics. Aerodynamic drag is proportional to the square
of velocity, and the
power needed to overcome drag is proportional to the cube of velocity. This
means that there is a very
strong relationship between the speed that a vehicle is travelling, and the
proportion of the fuel used to
overcome drag. Tail fairings have been applied to the back of trailers to
reduce drag. They are generally
2 to 3 feet long and are set at a converging angle in the range of 12 to 15
degrees. This angle creates
issues in that the angled fairings cover upper indicator lights and get in the
way of rear doors and
require complex support structures. Many of theses systems deploy with the use
of powered activation
devices which adds to cost and complexity. This invention teaches the use of
openings such as
perforations and slots in the rear fairings so that they that do not
necessarily converge but remain
parallel to the side of the object being steam-lined. Air is metered through
the openings to improve
laminar flow, reduce air flow , turbulence and pressures over rearmost edges.

Claims

Claims
l Claim
1. Panel(s) with openings mounted at the rear end of a moving vehicle where
said panel(s)
extends, wholly or in part, behind the end of the vehicle and is parallel to
the face of the vehicle
onto which it is attached.
2. Panel as in claim 1 where the openings are perforations
3. Panel as in claim 1 wherein the openings are slots
4. Panel as in claim 1 where in the openings are a screen material
5. Panel as in claim 1,2,3 and 4 wherein the panel is not parallel to the
face of the vehicle onto
which it is attached
6. Panel as in claim 1,2,3,4 and 5 wherein the openings are a combination of
perforations, slots
and screens or any combination thereof.
7. Panel as in claims 1 to 6 wherein said panel is movable from a position on
the vehicle to a
position where it wholly or partially extends beyond the trailing edge of the
vehicle
8. Panel as in claims 1 to 7 wherein said panel is mounted to a track to
facilitate deployment and
retraction
9. Panel as in claim 1 to 8 wherein a surface is attached to catch wind that
will deploy said panel so
that extends beyond the trailing edge of the vehicle
10. Panel as in claims 1 to 6 and 8 wherein said panel is deployed to extend
wholly or in part beyond
the trailing edge of the vehicle and return with the use of a linkage
assembly.
11. Panel as in claims 1 to 10 wherein said panels have a turbulation means on
their surface to
shape aerodynamic flow to diminish drag on the vehicle
12. Panel as in claims 1 to 11 wherein it may be retracted with a spring or
weight.
13. Panel with openings that is a part of the rear portion of a trailer.
Plural may be singular and Singular may be plural in above claims

Description

Description
There are a multitude of mechanisms available that reduce the aerodynamic drag
on transport trucks.
The amount of fuel required to power these vehicles is reduced when drag is
reduced. Aerodynamic
drag is proportional to the square of velocity, and the power needed to
overcome drag is proportional
to the cube of velocity. This means that there is a very strong relationship
between the speed that a
vehicle is travelling, and the proportion of the fuel used to overcome drag.
There are two types of drag reduction mechanisms being used presently. Tail
fairings that are
generally 2 to 4 feet in width are mounted to the rear of trailers. They are
mounted on the sides and
the top of a trailer and converge at a 10-degree to 15-degree angle to reduce
rear side turbulence and
drag. They are folded out of the way so that rear doors can be accessed. They
generally improve fuel
efficiency by 5%. Fairing deployment is facilitated by manual or powered
means. Some mechanisms are
deployed when the vehicle reaches a prescribed velocity. These mechanisms
require complex and costly
structures and devices to deploy and retract. The fairings and their
mechanisms operate in harsh
elements, and bear forces and vibrations inherent with highway use which lead
to greater levels of
mechanical failure.
The second type of mechanism for drag reduction is a series of tabs at the
tail edge of the vehicle that
shape the airflow around said tail edge to reduce drag. This is not as
effective as tail fairings as they
increase the frontal area of the vehicle and do not extend the shape of the
ensuing tail to the same
degree.
This invention uses fairings that extend beyond the rear of the vehicle but do
not necessarily converge
at an angle to the top or sides or bottom. They are deployed essentially
parallel to the face of the
vehicle to which they are attached. The fairings are deployed on tracks or
linkages or pivot pins or the
like to extend beyond the tail edge of the vehicle. Since the fairings do not
need to converge, the
deployment mechanism is greatly simplified and may be powered, manual or wind
powered with spring
or weighted return.
The fairings have openings that allow some air to pass through the fairings to
reduce turbulence over
their rear edge, laminarize air flow and reduce drag. The openings may be
slots, perforations or by
screen segment(s).
CA 3051082 2019-08-02